Synopsis On the evening of 23August 1995, the twin-hulled SHOWBOAT departed the eastern end of Ontario Place with 39 persons aboard, 6 of whom were crew members. About 10 minutes later, both engines failed and the vessel started to list to starboard. While moving ahead at a slow speed, the SHOWBOAT struck a sea wall causing many of those on board to lose their footing. The vessel heeled to starboard, the starboard main deck edge became submerged, and all on board fell into the water. The vessel downflooded, sank and settled upright on the bottom in 1.8metres of water. All on board were rescued and assisted to shore by the crew, the public and Ontario Place personnel. The Board determined that the uninspected SHOWBOAT was heavily laden, downflooding and slowly sinking before it struck the sea wall. There was no life-saving equipment on the vessel, but all on board were rescued promptly because the vessel sank close to shore in relatively shallow water. Contributing to the accident was the absence of clearly defined responsibility for the management of safety and for maintenance, the lack of guidance to the operators regarding the weight the vessel could carry safely, and the modification to the vessel's transom through which water downflooded. 1.0 Factual Information 1.1 Particulars of the Vessel 1.1.1 Description of the Vessel The vessel was reportedly built for its present owners in 1973. The manufacturer is no longer inbusiness. The hull consists of two long semi-elliptical hulls spanned by a deck. Above this deck, a second, flat, main deck extends from bow to stern. The space between these decks forms a compartment which is open at the stern above the transom. The transom extends across both hulls and forms a deep well in each. Fibreglass was delaminating from the wood construction in the engine wells, port and starboard, and water was seeping into the vessel. In each well, there is an automatic bilge pump with a capacity of about 1.3l/s. A 90hp outboard engine is mounted on the transom in both the port and starboard deep wells. On the lower deck, between the hulls, is mounted a generator. The weight of the motors and generator caused a permanent trim by the stern. At the bow, there is a small bulwark to deflect water and spray. The operator's control station is on the starboard side, immediately abaft this bulwark. A steel railing, with openings for boarding, encloses the main deck aft of the bulwark. Above the railing, there is a canopy supported by an aluminium framework. No seating is provided for those on board, with the exception of theoperator. In 1978, the two hulls were filled non-uniformly with aeromatic polyetherurethane foam. Under the lower of the two decks spanning the twin hulls, the foam compartments are about 33cm in height. The foam extends from about 1m from the after end (clear of the deep wells) to the bow. The volume of the foam was calculated to be about 3.6m3. The foam type was identified by a chemical analysis performed by the TSB Engineering Laboratory(3), and its dry density was established to be 0.22g/cm3. 1.2 History of the Voyage At 1900(4) on 23August 1995, 33 gospel singers, who had been hired by Ontario Place for a performance, boarded the SHOWBOAT to be transported to the area where they were to perform. On board, there was also a crew of six, who worked for the Entertainment department of Ontario Place. A quantity of musical equipment, speakers and amplifiers, the weight of which was unknown, was also brought aboard and located centrally on the main deck. All on board were situated within the area enclosed by the vessel's guard rail. The after main deck edge reportedly was approximately 3cm above the waterline when boarding was completed. The operators of the SHOWBOAT indicated that the method used to determine the vessel's maximum load was guesswork -- an indication of proper loading was whether the vessel looked right. The SHOWBOAT reportedly had been loaded several times in the past to a condition similar to that existing at the time of departure on the day of the occurrence. At 1915, the SHOWBOAT departed from a location adjacent to the eastern parking area of the Ontario Place main office for its destination about 1km away. The depth in the channel for most of the projected journey was over 3m. As the SHOWBOAT passed a finger dock of a marina facility, some people on shore observed that the stern was very low in the water, the exhaust ports of the two outboard engines were submerged and there was no freeboard aft. A minute later, they heard one of the engines stop and then the other. The operator attempted unsuccessfully to restart the engines. The SHOWBOAT was now without power or steering and was drifting ahead at an estimated 3to 3knots at an acute angle toward a sea wall on its starboard side. The vessel had developed a starboard list which was increasing. As the SHOWBOAT closed on the sea wall, one of the crew members attempted to cushion the impending impact by fending off with his legs. He was unable to do so, and the vessel's starboard shoulder struck the sea wall. The impact with the sea wall caused most of the people on board to lose their footing and move rapidly toward the starboard side. The vessel heeled some 45 degrees to starboard. The majority of the persons on board, including one who was disabled, fell into the water as the starboard main deck edge became submerged. The vessel then settled upright on the bottom with the bow projecting slightly above the surface. In this area, the water is between 1.5 and 1.8m deep. 1.2.1 Ontario Place Management Policy on Vessel Use At the time of the occurrence, a number of Ontario Place departments, i.e. RidesandAttractions, Entertainment, or Marine Activities, were using the SHOWBOAT for their own purposes on a first-come, first-served basis. The departments scheduled the activities of the SHOWBOAT; e.g. equipment and stage props could be transported throughout Ontario Place, or a band could play on the vessel while it proceeded through the park. Each department supplied its own operator and crew and was responsible for the operation and safety of the vessel while under its control. Ontario Place did not provide an on-board emergency plan for the safety of persons carried aboard the SHOWBOAT. Small fast boats, equipped with first aid equipment and radios are on patrol, but these may not necessarily be close in an emergency situation. There was no overall documented contingency plan to respond to emergencies such as in this instance. Hull and engine maintenance was performed by the Rides and Attractions section of the Maintenance department. There was no follow-up to ensure compliance with an Ontario Place directive that the individual departments using the vessel provide the necessary personal safety equipment on board the SHOWBOAT. There was no life-saving equipment of any type aboard the SHOWBOAT. Other Ontario Place small licensed vessels which transport the public are equipped with fixed seating and carry sufficient lifejackets and other life-saving equipment for each person on board. These vessels also are not subject to inspection by Transport Canada as they are not classed as passenger vessels and do not trade between provinces. Since the occurrence, all marine safety aspects of the operation of the SHOWBOAT and of Ontario Place passenger-carrying vessels have become the responsibility of the MarineOperations department. 1.3 Injuries to Persons Eight persons were reported to have suffered injuries including bruised or injured hands, hips, lower backs and ankles. 1.3.1 Rescue of Those on Board Most of the gospel singers were hampered by their gowns but were quickly assisted to shore by the crew, the public and Ontario Place personnel. They were attended to by a registered nurse, first aid and other Ontario Place personnel. Some of the gospel singers reported being hindered by crew who had remained on the vessel to attempt to remove sound equipment while the vessel was settling to the bottom. Other gospel singers were reported to have assisted in the recovery of the equipment. No one donned a lifejacket; none was available. 1.4 Damage to the Vessel The vessel sustained minor damage at the starboard bow at the same place where there had been previous minor damage. There was also minor water damage to the engines. Other damage occurred while the vessel was being salvaged. After salvage, the vessel was withdrawn from service and sold for parts. The replacement SHOWBOAT is of different design. 1.5 Certification 1.5.1 Vessel The vessel was licensed as a pleasure craft. 1.5.2 Personnel The operator of the SHOWBOAT was required to and did hold a Toronto Harbour Operator's licence issued by the Toronto Harbour Commission. He did not have any level of TransportCanada certification, nor was such certification required for this operation. 1.6 Personnel History The operator and crew of the SHOWBOAT had marine experience limited to seasonal employment with the Ontario Place administration. The operator had worked as such for several summer seasons. 1.7 Weather Information At the time of the occurrence, winds were light and visibility was good. Civil twilight commenced at 2008. 1.8 Radio Communication The crew operating the boat was in radio contact with the Ontario Place main office by means of portable radios equipped with an ultra-high frequency (UHF) band and a very high frequency (VHF) band. The VHF band radio frequency in use was not a marine frequency. These portable radios performed satisfactorily. 1.9 Life-saving Equipment The SHOWBOAT did not comply with the requirements respecting life-saving equipment as prescribed by the Canada Shipping Act for a vessel of its size and class. At the after end of the vessel, directly beneath the canopy, is a screen grating designed for lifejacket storage. At the time of the occurrence, there was no lifejacket nor personal flotation device stowed there. The vessel did not carry a liferaft, any form of flotation device, a lifebuoy, an anchor or a sternlight, nor were there any emergency pyrotechnics aboard. 1.10 Modification to the Transom An opening of some 18cm in diameter had been cut in the transom to create an air flow to the generator. A coping designed to prevent water from downflooding to the generator space had been fitted over the hole. It is unknown when this modification had been carried out. The upper edge of this coping is 11cm below the extension of the main deck edge. It was reported that the water was within approximately 3cm of the deck edge at the time of departure. If the report is correct, the top of the coping was under water at this draught, and water was flooding into the vessel. This was not observed by the crew, but the inflow was countered to some extent by the two bilge pumps, one port and one starboard. The combined capacity of the pumps was about2.6l/s. 1.11 Railing -- in Comparison to Passenger Vessels The railing on the vessel rises 737mm above the deck with posts 305mm apart without any strong netting. On a passenger vessel, rail posts must be no more than 229mm apart, unless strong netting is provided, and the perpendicular height must not be less than 1,067mm above the deck. 1.12 Stability There is no regulatory requirement for the submission of stability data for a pleasure craft; however, the SHOWBOAT is generally used as a multi-function utility boat, depending on the needs of the departments using it. The vessel frequently carries more than 12 persons and varying amounts of cargo, but the people it transports do not fit the definition of passenger as found in the Canada Shipping Act. For the purposes of the stability calculations in this report, STAB.5, Standard for the Intact Stability of Passenger Vessels Carrying More than 12 Passengers, of the Stability, Subdivision, and Load Line Standards (TP7301) and the Construction Standards for Small Vessels (TP1332) were used as references. The calculation of the transverse stability characteristics of a vessel is based upon the ideal static sea state, and in actual dynamic sea conditions, angles of roll are usually greater than those calculated by the static methods. The interacting effects of wave-induced motion, wind, and vessel speed, subject the calculated reserve stability of small vessels to considerable fluctuation. In this instance, the simultaneous interaction of a number of separate dynamic effects, such as the shift of the vessel's centre of gravity due to people moving about the deck and the virtual rise of the centre of gravity due to the presence and movement of free surface water, overcame the vessel's remaining righting ability. 1.12.1 Inclining Experiment The vessel was measured and inspected while out of the water. Once refloated, it was prepared for an inclining experiment to determine its basic stability characteristics. The experiment, conducted on 30August 1995(5), consisted of shifting weights transversely across the deck of the vessel when it was free to heel. The angle of heel was measured by the shift of a plumb line along a graduatedscale. For analysis purposes, the weight of 39 persons was used to approximate the vessel's loaded condition at the time of the accident. The inclining experiment determined that the lightship weight of the SHOWBOAT was 3,836kg, with a vertical centre of gravity (VCG) of 0.72m. 1.12.2 Quantity of Water Shipped The departure condition at 1915 is unknown, except that the stern freeboard was observed as being approximately 3cm below the main deck edge. The total displacement of the vessel when it struck the sea wall at 1925, as determined from information gathered and by calculation, was about 13,500kg. The average weight of the people involved in the occurrence was probably greater than the 63.5kg per person used as a standard in STAB.5. This extra weight and the weight of the sound and musical equipment aboard were estimated to have been about 250kg. Thus, it is concluded that the vessel had taken on a total of about seven tonnes of water. 1.12.3 Small Vessel Capacity Plate The tonnage of the SHOWBOAT was determined to be under five gross tons. The Ontario Place administration had licensed the vessel as a pleasure craft under the Small Vessel Regulations. Since the vessel was over 5m in length, Section3 of PartI of the Construction Standards for Small Vessels, which deals with Capacity Plates, did not apply. This plate, which gives the safe maximum load and recommended outboard motor size, is permanently attached to a vessel in a plainly visible position on board.